Three-dimensional printer



FIG. 1 is a front perspective view of a three-dimensional printer showing our new design;

FIG. 2 is a front view thereof;

FIG. 3 is a rear view thereof;

FIG. 4 is a left side view thereof;

FIG. 5 is a right side view thereof;

FIG. 6 is a top plan view thereof; and,

FIG. 7 is a bottom plan view thereof.

The broken lines in the drawings are for the purpose of illustrating unclaimed portions of the three-dimensional printer and form no part of the claimed design. 

CLAIM The ornamental design for a three-dimensional printer, as shown and described. 